aa_match test cases, minor aa_match refactor

casanovo/denovo/evaluate.py

@@ -162,10 +162,10 @@ def aa_match(
         Boolean flag to indicate whether the two peptide sequences fully match.
     """
     if peptide1 is None and peptide2 is None:
-        return np.array([], dtype=bool), False
-    elif (peptide1 is None) != (peptide2 is None):
+        return np.empty(0, dtype=bool), False
+    elif peptide1 is None or peptide2 is None:
         peptide = peptide1 if peptide2 is None else peptide2
-        return np.array([False] * len(peptide)), False
+        return np.zeros(len(peptide), dtype=bool), False
     elif mode == "best":
         return aa_match_prefix_suffix(
             peptide1, peptide2, aa_dict, cum_mass_threshold, ind_mass_threshold

tests/unit_tests/test_unit.py

@@ -14,6 +14,7 @@
 import unittest
 import unittest.mock
 
+import depthcharge.masses
 import einops
 import github
 import numpy as np
@@ -24,7 +25,7 @@
 from casanovo import utils
 from casanovo.data import ms_io
 from casanovo.data.datasets import SpectrumDataset, AnnotatedSpectrumDataset
-from casanovo.denovo.evaluate import aa_match_batch, aa_match_metrics
+from casanovo.denovo.evaluate import aa_match_batch, aa_match_metrics, aa_match
 from casanovo.denovo.model import Spec2Pep, _aa_pep_score
 from depthcharge.data import SpectrumIndex, AnnotatedSpectrumIndex
 
@@ -846,6 +847,20 @@ def test_eval_metrics():
     assert 26 / 40 == pytest.approx(aa_recall)
     assert 26 / 41 == pytest.approx(aa_precision)
 
+    aa_matches, pep_match = aa_match(
+        None, None, depthcharge.masses.PeptideMass().masses
+    )
+
+    assert aa_matches.shape == (0,)
+    assert not pep_match
+
+    aa_matches, pep_match = aa_match(
+        "PEPTIDE", None, depthcharge.masses.PeptideMass().masses
+    )
+
+    assert np.array_equal(aa_matches, np.zeros(len("PEPTIDE"), dtype=bool))
+    assert not pep_match
+
 
 def test_spectrum_id_mgf(mgf_small, tmp_path):
     """Test that spectra from MGF files are specified by their index."""